In this paper, the design ideas including the software and the hardware such as key electric circuits of the automatic weather station based on embedded Linux operating system are introduced. The high resolution ADC (analog-to-digital convertor) is used to achieving data characters. The system based on the bus structure makes the system can be connected with various weather sensors. Any substitution of the weather sensors neither need to change the software nor the hardware of main collector. Not only the program source codes are given, but also some essential problems which should be paid attention are suggested. Practical application shows that this system has advantages such as high precision，high stability, low power consumption. Experimental results proof that the system is accordance with the design criteria of the second-generation automatic weather station in China.

The data transmission scheme between a transmission control protocol/internet protocol (TCP/IP) network port and a serial port based on an ARM embedded system is introduced in the paper. The data transmission between a personal computer (PC) and remote equipment through an Internet is realized. The structure of a hardware platform is simply introduced, the cutting and transplant of operating system, the communication program design of the network port and the serial port and the cross compiling between the two ports are introduced in detail. The AT91SAM9261 chip of ATMEL Corporation is employed as the embedded board of a kernel processor. The Redhat9 Linux operating system is employed as a software development platform, an ARM-Linux operating system is employed as a program operation platform and the kernel version is Linux-2.6.2. The C program is used and an ARM-Linux-GNU tool chain is used for the cross compiling. The experimental result proves that the real-time, parallel full duplex data transmission between the network port and the serial port is realized by the scheme provided in the paper.

An unavoidable disadvantage of most traditional sampling methods is the large amount of samples data preservation during sampling process. Equivalent Time Sampling is a popular sampling method which usually used in oscilloscope technology. When input signals have the similar features as the jump signal, whose information focus in a very short period of time, the Equivalent Time Sampling’s disadvantage will become more obvious. This paper proposed a new sampling method named Vertical Sampling based on testing time via ADC. High-speed voltage comparator, ADC, and mathematical model between phase and time are used in this method. The whole system obtains unknown input signal’s tendency information and the time difference information to accomplish the sampling process. Experimental results proved this new method’s effectiveness on reducing the samples for three kinds of signals especially for the jump signals.